Karl Friston: belief

Transcript context

…You could if you wanted to simulate these kinds of things, you could read the DNA as the code that the priors that specify the structure. And, you know, I think that if if if you think of DNA as prescribing the structure of your generative model or your world model or your factor graph that will be fit for purpose and is learnable. So you start off with say DNA. DNA does not tell you what particular kind of plant you're going to be, where it's not going to tell you how to engage in your phototaxis and point towards the sun or compete with other plants that are trying to deny you sunlight. That is something that you have to update and learn during your particular lifetime. But you're equipped with the basic structure, the prior on the structure of your generative model. And of course that is most gracefully accommodated I think again with respect to the renormalization group. We're just talking about 2 scales. So you've a slow scale where you've got the you mentioned before viral mutation. So the viral DNA, should it have RNA or DNA, is changing very very slowly on a timescale that is greater than or equivalent to the lifespan of any given virus. And that's, if you like, specifying the initial conditions, the structure for the specification of a particular instance of a virus. Maybe just jump in for a minute because I think actually it's not even specifying the structure. Think it and this is what you pointed out before about the difference between say active inference versus modeling is actually the DNA is specifying a policy. Yes. It's It's effectively just specifying a policy that every single cell in the organism follows. And so this policy is not instructions for a structure, but it's just instructions on what to do in response to a certain set of sensory states. Right? So it's almost it's the policy that the DNA specifies, and this policy applies to every cell. And then somehow miraculously, it works out to create a structure that is fit for purpose in its particular environment. Yes. Yeah. And of course, to work, that specification has to change at the same rate at which the environment changes, which is very, very slowly. I think that's absolutely right. Mean, just practically, that hits you in the face when it comes to thinking about how you commit to 1 policy or another policy. So in my world, that would be the expected free energy. The expected free energy comes in 2 parts. It has a sort of expected information gain and the expected cost or constraints or utility and that is at the point you need your DNA. You know need what it is to be the kind of thing that I am. What do I not do and what do I do? And the fascinating things in organisms is this is different even on a cell by cell level. Right? Because morphologically,…

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